Keyhole-guard.



T. E. DUNLAP.

KEYHOLE GUARD.

APPLICATION FILED JUNE 12, 1914.

1,140,258. Patented May 18, 1915.

THE NORRIS PETERS C0,, PHOTO-LITHQ WASHINGTUN, D. C

THOMAS E. DUNLAP, OF NEW ORLEANS, LOUISIANA.

KEYI-IOLE-GUARD.

mamas.

Application filed June 12, 1914.

To all whom it may concern:

Be it known that I, THOMAS E. DUNLAP, a citizen of the United States of America, residing at New Orleans, parish of Orleans, State of Louisiana, have invented certain new and useful Improvements in Keyhole- Guards, of which the following is a specification.

The present invention has reference to safety devices for door locks, and it proposes, briefly, an improved guard which 1s designed for insertion into the key-hole of a door look, from the inside, after the bolt has been shot and the key withdrawn, the construction and arrangement of the guard being such that it is enabled to act as a plug which is rigidly secured in the key-hole and fills the same, thus preventing the introduction of a skeleton key into, as well as peeping through, the key-hole.

An embodiment of the invention is illustrated in the accompanying drawing, whereof Figure 1 is a perspective view of the complete guard, showing the position of the various parts just prior to its insertion into the lock; Fig. 2 is a part-sectional plan view, showing the guard inserted; and Fig. 3 is a plan view of the blank from which the guard proper is constructed.

Referring more particularly to said drawing, it will be seen that the device as a whole consists of but two elements, namely :the guard proper 1, and its actuator 2. The former element consists of a pair of flat metal jaws 3, 3, which are welded or otherwise fastened together at their outer ends and are connected at their inner ends by a spring bow 4, the said bow tending to normally close the jaws against each other. In the construction illustrated, which, for present purposes, may be considered as preferred, the element in question is shown as made from a single blank of spring metal of the shape represented in Fig. 3, which may be readily stamped from a sheet of material by means of a suitable die, the central portion of the blank, which forms the aforementioned bow, having a somewhat greater width than the jaws. When the end portions of the blank are folded against each other and fastened together at their terminals in the manner above indicated, it will be apparent, therefore, that the said end portions, which, as will be understood, constitute the jaws of the guard, also unite in Specification of Letters Patent.

Patented May 18, 1915.

Serial No. 844,788.

forming the shank thereof, while the central or bow portion also acts as a handle, by means whereof the said shank is inserted through the key-hole 5 in the escutcheon plate 6 into the look, (not shown). The other element of the device, a, the actuator 2), is utilized to open or expand the jaws, and is here shown as in the nature of a key embodying a threaded shank 7 provided at one end with a head or handle 8 and having its opposite end 9 pointed, the shank being engaged in a threaded opening 10 formed in the center of the how 4:. Ac-

cordingly, when the key is rotated in the proper direction to cause it to move inwardly through said opening, its point will be forced between the inner ends of the jaws, thus spreading or separating the same, said jaws automatically assuming their normally-closed position when the key is re tracted. lVhile the key is to all intents and purposes complete as above described, it may, if desired, be furnished with a crosspin 11, which is suitably affixed to its shank in such a way as to contact with the inner face of the bow when the key has been retracted to a certain extent, thereby preventing further backward or outward move ment.

The shank of the guard, as previously stated, is designed for insertion through the key-hole, from the inner side of the door, and in order to prevent its unauthorized withdrawal, either accidentally or otherwise, it is equipped with retaining means which, when the jaws of the shank are opened, are adapted to engage some suitable part of the lock, in the present instance, the escutcheon plate 6. The said means may advantageously consist, as shown, of pairs of spaced shoulders which engage the opposite faces of the said plate at the edges of the key-hole, the shoulders being formed in any desired manner, preferably, however, by providing the outer faces of the jaws with transverse grooves 12 wherein the edges of the plate at the point specified fit. In this case, as will be apparent, the shoulders are constituted by the side walls of the grooves, the latter being of sufficient depth to exercise the desired retaining action without materially weakening the jaws.

In use, the shank of the guard is inserted through the key-hole until the grooves 12 are opposite the edges of the escutcheon plate wherein the key-hole is formed. The key 2 is then turned in the proper direction to expand the shank jaws, thus causing the plate edges to enter said grooves and, in consequence, locking the guard against removal until the key point is withdrawn from between said jaws. When so positioned, the guard shank will completely seal the keyhole and will prevent the entrance thereinto of a skeleton key or of any thin or narrow instrument which might ordinarily be inserted for the purpose of disengaging the jaws from the plate, while, at the same time, the provision of the bowed handle prevents inspection of the interior of the room or other part of the building through the crevices left uncovered at the enlarged upper end of the key-hole.

I olaim:

1. A key-hole guard comprising a pair of jaws arranged with their inner longitudinal faces in mutual contact and adapted for insertion through the key-hole in the escutcheon plate, said jaws having their outer ends rigidly fastened together; and a spring bow connected with the inner ends of said jaws for normally holding the said faces thereof in such contact.

2. A key-hole guard comprising a pair of jaws arranged with their inner longitudinal faces in mutual contact and adapted for insertion through the key-hole in the escutcheon plate, said jaws having their outer ends rigidly fastened together and being provided with locking means for engagement with said plate at the edges of said keyhole; and a bow connected with the inner ends of said jaws for normally holding the said faces thereof in such contact.

3. A key-hole guard comprising a pair of jaws arranged with their inner longitudinal faces in mutual contact and adapted for in-.

sertion through the key-holein the escutcheon plate, said jaws having their outer ends rigidly fastened together and being provided with locking means for engagement with said plate at the edges of said key- 1 hole; a bow connected with the inner ends of said jaws for normally holding the said faces thereof in such contact; and means for separating said jaws, to bring said looking means into such engagement.

4. A key-hole guard comprising a pair of jaws arranged with their inner longitudinal faces in mutual contact and adapted for insertion through the key-hole in the escutcheon plate, said jaws having their outer ends rigidly fastened together; a spring bow connected with the inner ends of said jaws for normally holding the said faces thereof in such contact; and means for expanding said jaws, to cause the same to grip said plate at the edges of said key-hole.

5. A key-hole guard comprising a pair of jaws arranged with theirinner longitudinal faces in mutual contact and adapted for insertion throu h the key-hole in the escutcheon plate, sai 'aws having their outer ends rigidly fastened together; a spring bow connected with the inner ends of said jaws for normally holding the said faces thereof in such'contact; and an endwise-movable element having a pointed end adapted for introduction between the inner ends of said I jaws, to spread the latter and cause them to and a springbow connected with the inner ends of said jaws.

7. A key-hole guard comprising a pair of juxtaposed jaws rigidly fastened together at their outer ends and adapted for insertion through the key-hole in the escutcheon plate; a spring bow connected with the inner ends of said jaws for normally holding said jaws in closed position, said bow having a central opening formed therewith; and

a member movable endwise through said opening and having a pointed end adapted for introduction between-the inner ends of said jaws, to spread the latter and cause them to grip said plate at the edges of said key-hole.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

THOMAS E. DUNLAP. Witnesses:

Ronnnr VVATERMAN, CHARLES H. NASH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

